Mold



June 21, 1938. c. A. MENZEL 2,121,439

MOLD Filed July 16, 1937 2 Sheets-Sheet 1 Patented June 21, 1938 UNITED STATES PATENT OFFICE MOLD Carl A. Menzel, Homewood, Ill.

Application July 16, 1937, Serial No. 153,976

.LIIIS invention relates to molds and has for its principal object to provide amold for making test bars of Portland cement and such like of uniformly accurate dimensions.

Some Portland cement contains magnesium and calcium that enlarge with age and when used as an ingredient in concrete cause the latter to expand with age. Instances are reported in which concrete bridge piers have grown as much as six 10* inches. Aside from the fact that such change of dimensions is often intolerable in engineering construction, the enlargement or growth appears to be accompanied by breaking down of the concrete. I

Chemical analysis cannot be relied upon to determine the presence or absence of the unsound constituents in deleterious quantities in a particular lot of cement.

The growth which normally takes years can 20 be produced artificially by putting the cement or concrete in a moist atmosphere at about 425v Ffand 300 lbs. pressure for approximately five hours, or at 120 lbs. pressure and 350 F. for forty-eight to seventy-two hours.

By measuring test bars before and after this pressure cooking the presence of the undesirable ingredients can be learned with reasonable quickness.

Molds embodying this invention are especially 30useful in making test bars of neat Portland cement.

Further objects and advantages of the invention will appear as the description is read in connection with the accompanying drawings, in

35 which 7 Fig. 1 is a plan View of a gang mold for making eight test bars five inches long and one inch in cross section;

Fig. 2' is a similar plan View broken away and 4 showing the same mold assembled to make test bars ten inches long and of the same cross section;

Figs. 3 and 4 are sections taken on the lines 3-3 and 4-4 respectively of Fig. 1;

'Fig. 5 is a longitudinal section through one of thetest bars and two of the end blocks as that assembly comes from the mold;

Fig. 6 is a side elevation of a test bar with the end blocks removed, and

Fig. 7 is a perspective View of one of the end blocks.

But these particular drawings and the corresponding description are used for the purpose of illustration only and are not intended to impose 5 ,unnecessary limitations on the claims.

The foundation of the mold is a base ID of cast iron, steel, or the like, finished to an accurate plane on its upper surface ll, drilled and tapped to provide three sets of threaded openings l2 and strengthened by marginal flanges l3 and 5 intermediate ribs I 4. The marginal flanges are cut away to form what are, in effect, feet I5 at the corners and I6 approximately midway between the corners.

Assembled on this base is a frame comprising 0 end bars I! and side bars 18, the latter having their ends secured in notches I9 in the end bars by bolts 20.

Between the side bars [8 are intermediate side bars, or spacer bars 21 separated by end blocks 22 to form with the side bars I 8, a series of mold cavities 23.

Each end block 22 is secured to the corresponding end bar II by a bolt 24 which passes through an opening 25 in the end bar and is threaded into a transverse opening 26 in the end block.

The inner ends of the bolts 24 are machined or ground fiat and the dimensions are such that the distance between aligned fiat faces of each pair of bolts 24 is exactly the length of the required test bar. In the present illustration that distance is five inches, as shown in Fig. 1, and ten inches as shown in Fig. 2.

A stainless steel measuring stud 21, knurled at 28 and threaded at 29, is inserted into each end block 22 so as to leave a portion projecting therefrom into the mold cavity. In the illustrated embodiment the socket for the stud is the threaded opening for the bolt 24, and a' stud is screwed into each end block 22 against the flat face of the corresponding bolt 24. The contacting face 30 of the measuring stud is spherical and is preferably polished. The knurled heads 28 of the measuring studs project into the mold cavities 23 and are thus embedded in the test bars 3| formed therein. Hence the polished spherical ends or surfaces 30 mark the ends of the test bars between which measurements are taken in. a suitable comparator before and after the bars are subjected to treatment to accelerate their growth.

The frame of the mold is made fast to the plate II] by four bolts 32 screwed into two sets of the threaded openings l2.

When test bars of five inches in length are to be made, short side and intermediate or spacer bars are used and one of the end bars ll is made fast in the intermediate position shown in Fig. 1. When test bars of ten inches in length are to be made, long side and intermediate bars I8 and 2| are used, and the end bars are secured to the remote sets of threaded openings [2.

In operation the gang mold is assembled after each part has been covered with a thin coat of stearate or petroleum jelly. Stearate may be prepared by dissolving one part by weight of stearic acid in two and one-half parts of kerosene at 150 F.

As a rule it will be found preferable to assemble the end bars I! and side bars I8 first drawing up the bolts 20 lightly by hand, and then to place these parts on the base plate l0 and insert the bolts 32. Thereafter the intermediate or spacer bars 21 are set in approximate positions and the end blocks inserted and made fast by the bolts 24, which are also drawn up by hand. The bolts 32 then are tightened, and finally the measuring studs 2'! are inserted and run up by hand.

The neat cement to be tested should be mixed according to sections 19 to 22 of Standard Methods of Sampling and Testing Portland Cement (A. S. T. M. Designation: C77-32). Immediately after being mixed, each mold cavity should be filled with three layers, each layer being compacted by hand with the forefinger protected by a rubber glove.

After the top layer has been compacted the bar should be smoothed off with a few strokes of a trowel, leaving the mixture slightly above the sides of the mold. Immediately afterwards the mold should be covered with damp burlap, but care should be taken not to let the burlap come in contact with the surface of the cement. After approximately two hours the surface should be finished with a trowel and identifying numbers inscribed thereon with steel dies. Also at this time the bolts 24 holding the end blocks should be loosened to permit free movement of the measuring studs due to shrinkage during the setting period. The mold with its contents should then be put in a moist closet for approximately 22 hours, after which the bolts 24 should be removed, the bolt 23 loosened and the test bars with the assembled end blocks taken out. The end blocks may then be removed by simply unscrewing them from the studs 27 thus leaving the test bars as indicated in Fig. 6. They should then be put in warm water maintained at uniform temperature as, for example, F.

Approximately one hour after being removed from the mold the test bars should be surface dried with a cloth and immediately weighed and measured for length after which they should be returned to the water where they are kept until they are put through the autoclave and again measured'to learn the change wrought by that treatment.

I claim 1. In a mold, means defining a mold cavity having an end wall, an end block having a single transverse opening extending entirely through it, and means setting through the end wall and. partially through the opening in the end block to mount the end block in the cavity adjacent the end wall, the remainder of the opening being adapted to receive a stud which extends from the end block into the mold cavity, whereby the stud is adapted to become secured in a casting formed in said cavity and whereby the casting and attached end block may be detached from the means defining the mold cavity and the end block may thereupon be detached from the casting and stud.

2. In a mold, means defining a mold cavity having end walls, end blocks each having a single transverse opening extending entirely through it, and means setting through the end walls and partially through the openings in the end blocks to mount the end blocks in the cavity adjacent the end Walls, the remainder of each opening being adapted to receive a stud which extends from the end block into the mold cavity, whereby said studs are adapted to become secured in a casting formed in said cavity and whereby the casting and attached end blocks may be detached from the means defining the mold cavity and each end block may thereupon be detached from the casting and stud.

3. In a mold, means defining a mold cavity having end walls, end blocks each having a single transverse threaded opening extending entirely through it, and bolts setting through the end walls and partially through the openings in the end blocks to screwthreadedly mount the end blocks in the cavity adjacent the end walls, the remainder of each opening being adapted to receive a stud which extends from the end block into the mold cavity, whereby said studs are adapted to become secured in a casting formed in said cavity and whereby the casting and attached end blocks may be detached from the means defining the mold cavity and each end block may thereupon be rotated relatively to the casting to unscrew it therefrom.

4. In a mold, a base, a frame on the base comprising a pair of side bars and a pair of end bars surrounding a mold cavity, end blocks each having a single transverse opening extending entirely through it mounted between the pair of side bars, and means setting through the end bars and partially through the openings in the end blocks to mount the end blocks, the remainder of each opening being adapted to receive a stud which extends into the mold cavity, whereby said studs are adapted to become secured in a casting formed in said cavity and whereby the casting and attached end blocks may be detached from the base and bars and each end block may thereupon be detached from the casting and stud.

5. In a mold, a base, a frame on the base comprising a pair of side bars and a pair of end bars surrounding a mold cavity, end blocks each having a single transverse threaded opening extending entirely through it mounted between the pair of side bars, and bolts setting through the end bars and partially through the openings in the end blocks to secure the end blocks to the end bars, the remainder of each opening being adapted screwthreadedly to receive a stud which extends into the mold cavity, whereby said studs are adapted to become secured in a casting formed in said cavity and whereby the casting and attached end blocks may be detached from the base and bars and each end block may thereupon be rotated relatively to the casting to unscrew it therefrom.

6. In a mold, means defining a mold cavity having end walls, end blocks each having a transverse socket opening into the mold cavity and adapted to receive a stud which projects into the cavity, and means removably mounting the end blocks in the cavity adjacent the end walls, whereby the projecting portions of said studs are adapted to become secured in a casting formed in said cavity and whereby the casting and attached end blocks may be detached from the means defining the mold cavity and. the end blocks may thereupon be detached from the casting and from the socketed portions of the studs.

7. In a mold, means defining a mold cavity having end walls, end blocks each having a single transverse, threaded socket opening into the mold cavity and adapted to receive a threaded stud which projects into the cavity, and means removably mounting the end blocks in the cavity adjacent the end walls, whereby the projecting portions of said studs are adapted to become secured in a casting formed in said cavity and whereby the casting and attached end blocks may be detached from the means defining the mold cavity and each end block may thereupon be rotated relatively to the" casting to unscrew it therefrom and from the socketed portion of the stud.

CARL A. MENZEL. 

